Typically Developing Children Research Articles

Peer-mediated education and autism spectrum disorder (ASD) in preschool inclusive programs: the power of games

ABSTRACT This study investigated how peer-mediated structured game activities changed and improved peer relations in an inclusive preschool classroom for a child with autism spectrum disorder (ASD). A case study was used in which 17 typically developing (TD) children aged 60–71 months, a 66-month-old boy diagnosed with ASD and the preschool teacher participated. Data were collected before and after peer-mediated structured game activities. The peer tutors engaged in structured activities with the child with ASD for six months. Interviews and observations, picture sociometry, researcher’s diary, teacher’s diary, and structured play were used to collect the data. The findings revealed significant differences in participants’ functional skills before and after the peer-mediated structured game activities. It was observed that the TD children and the boy with ASD improved their social, emotional, and language skills. Children played together for longer. Play time increased, the number of participating children increased. Typically developing children cooperated more and assumed more responsibility. The child with ASD tried to produce meaningful words and participation in play activities was observed. In addition, the peer-mediated structured activities positively supported the teacher’s classroom management and classroom climate. In addition, the teacher’s level of practical knowledge improved.

Challenges with computing scalar and ad-hoc implicatures in Mandarin-speaking 4–8-year-old autistic children

IntroductionMixed findings have been reported about the computation of scalar or/and ad-hoc implicatures in primarily school-age autistic verbal children and adolescents: while some studies reported their struggles with both implicatures, others observed their strengths in computing scalar implicatures. This study extends the previous investigation by testing the derivation of scalar (including both number and quantifier) and ad-hoc implicatures of a younger group of Mandarin-speaking autistic 4–8-year-olds; moreover, we assess the biological, linguistic, and cognitive factors affecting children's implicature acquisition. MethodsThe participants included 22 4–8-year-old autistic verbal children (mean age = 67.64 months) and 19 typically developing (TD) children who did not significantly differ in age, receptive vocabulary, and non-verbal IQ. Both groups completed a computer-based Truth Value Judgment task, assessing their knowledge of scalar (involving the number ‘three’ and the quantifier ‘some’) and ad-hoc implicatures. We also examined whether their implicature computation was linked to age, receptive vocabulary, non-verbal IQ, and Theory of Mind (ToM). ResultsCompared with the TD controls, autistic children derived significantly fewer scalar and ad-hoc implicatures. Specifically, TD children successfully computed number and ad-hoc implicatures, contrasting to the bimodal distribution of their pragmatic vs. logical responses to quantifier implicatures. Though autistic children performed better with number implicatures slightly above the chance level, they had difficulties in computing quantifier and ad-hoc implicatures. Further, autistic children's knowledge of the number and ad-hoc implicatures was linked to their ToM skills. ConclusionsThese findings underscore the overall delayed implicature knowledge of young autistic children, and their low sensitivity to the implicatures is related to the core ToM deficits. Furthermore, our data confirm the coherent pattern of the earlier acquisition of number over quantifier implicatures and illuminate the distinct mechanisms underlying the computation of scalar vs. ad-hoc implicatures.

Parenting Stress in Autistic and ADHD Children: Implications of Social Support and Child Characteristics.

High levels of parenting stress have been detected in mothers of children with Autism (ASD) and children with attention deficit hyperactivity disorder (ADHD) comparing with mothers of typically developing (TD) children. The current study explored the implications of social support (confidant and affective support) and child characteristics (emotional, behavioral and sleep problems) on parenting stress in ASD and ADHD. Furthermore, the differences between mothers of children with autism, ADHD and TD on the studied variables were examined.A total of 120 mothers of 30 TD children, 47 with ASD without intellectual disability and 43 with ADHD collaborated in the study. Significant differences were found between clinical and TD groups in parenting stress, social support, and child characteristics.Correlation analysis in the group with ADHD revealed that parental stress correlated significantly with social support and with children's emotional problems. In the ASD group, parental stress also correlated significantly with children's sleep and behavioral problems. Moreover, multiple regressions showed that confidant support was a significant predictor of parenting stress in both clinical groups.The findings provide new insights to consider social support as a fundamental part of treatments for parenting stress in mothers of children with ASD and ADHD.

A Review of Childhood Developmental Changes in Attention as Indexed in the Electrical Activity of the Brain

A Review of Childhood Developmental Changes in Attention as Indexed in the Electrical Activity of the Brain

Handwriting difficulties in children with dyslexia: Poorer legibility in dictation and alphabet tasks, slowness in the alphabet task.

Several studies have shown that children with dyslexia (DYS), in addition to their reading and spelling deficits, encounter handwriting difficulties that are still poorly understood in terms of their nature and origin. The present study aimed to better understand the handwriting difficulties of children with DYS by comparing their handwriting quality and speed in two tasks, a dictation task and an alphabet task, which required fewer spelling skills than the dictation task. Twenty-nine French-speaking children (Mage = 9.5 years) participated in the study, including 18 children with DYS and nine typically developing (TD) children matched on chronological age. The children performed control tasks, a dictation task with words varying in graphic and orthographic complexity and an alphabet writing task. Accuracy, handwriting quality (legibility), and fluency (speed, writing and pause time) were carefully measured using a digital tablet. GLMM analysis and t tests showed that children with DYS made more aesthetic errors (handwriting quality) in both the dictation and alphabet task than TD children. They also wrote more slowly than TD children in the alphabet task (speed, pause time). These findings suggest that children with DYS present handwriting difficulties, even in a simple alphabet task. In dictation, they seem to favour speed at the expense of handwriting quality.

Characterization of speech and language phenotype in the 8p23.1 syndrome.

The 8p23.1 duplication syndrome is a rare genetic condition with an estimated prevalence rate of 1 out of 58,000. Although the syndrome was associated with speech and language delays, a comprehensive assessment of speech and language functions has not been undertaken in this population. To address this issue, the present study reports rigorous speech and language, in addition to oral-facial and developmental, assessment of a 50-month-old Turkish-speaking boy who was diagnosed with the 8p23.1 duplication syndrome. Standardized tests of development, articulation and phonology, receptive and expressive language and a language sample analysis were administered to characterize speech and language skills in the patient. The language sample was obtained in an ecologically valid, free play and conversation context. The language sample was then analyzed and compared to a database of age-matched typically-developing children (n = 33) in terms of intelligibility, morphosyntax, semantics/vocabulary, discourse, verbal facility and percentage of errors at word and utterance levels. The results revealed mild to severe problems in articulation and phonology, receptive and expressive language skills, and morphosyntax (mean length of utterance in morphemes). Future research with larger sample sizes and employing detailed speech and language assessment is needed to delineate the speech and language profile in individuals with the 8p23.1 duplication syndrome, which will guide targeted speech and language interventions.

The implication of sleep disturbances on daily executive functioning and learning problems in children with autism without intellectual disability

BackgroundIndividuals with autism spectrum disorder (ASD) often have sleep disturbances, executive functioning difficulties, and learning problems. The aim of this study was twofold. First, to examine the quality of sleep in children with ASD without intellectual disability and typically developing (TD) children. Second, to explore the implication of sleep disturbances in the association between daily executive functioning and learning problems in children with ASD without intellectual disability. MethodThe sample included 47 children with autism without intellectual disability and 32 TD children. Parent-reported questionnaires were used to assess participants' sleep disturbances, daily executive functions, and learning problems. All statistical analyses performed were adjusted for age, IQ, and medication. ResultsAs expected, the prevalence of sleep disturbances was significantly higher in the ASD group than in the TD group. Regarding the second aim of the study, the total score of sleep disturbances was significantly associated with learning problems and the metacognition subdomain of executive functioning in children with autism without intellectual disability. In turn, executive functions and learning problems were also significantly associated. Finally, sleep disturbances were found to mediate the relationship between global executive functioning and learning problems in children with ASD without intellectual disability. ConclusionsThe findings suggest that sleep disturbances are common in children with autism, and that they play a mediating role in the association between executive functions and learning problems. Therefore, sleep should be a crucial aspect of interventions to improve the learning and academic performance of school-aged children with ASD without intellectual disability.

Examining the feasibility of immersive virtual reality to measure upper limb motor performance in typically developing children and adolescents

Over the last five years, virtual reality (VR) has become more popular in pediatric physiotherapy. In this study, we assessed the feasibility and acceptability of measuring upper-limb movements in typically-developing children and adolescents using an immersive virtual reality (iVR) headset. Thirty-six typically-developing children (age: 12 ± 2.1 y) were recruited and required to draw circles in a custom-built virtual environment using a Meta-Quest-2 headset. Outcomes were the System Usability Scale (SUS), Developmental Coordination Disorder-Questionnaire (DCD-Q), and three metrics of circle drawing performance (movement time, mean velocity and circle roundness). The mean score for the SUS was 74 ± 11, indicating good levels of acceptability and usability when the participants used the headset. No strong relationships were observed between the circle drawing metrics and DCD-Q scores (rho = < 0.3, p = > 0.05), but circle roundness ratios were positively and significantly correlated with SUS scores (rho = 0.5, p = 0.003). No adverse effects associated with iVR use were reported for any participants. This study showed that iVR is a viable method to measure upper-limb motor performance in children and adolescents, highlighting the potential value of this tool in pediatric physiotherapy practice.

The relationships between motor skills and executive functions in children with and without autism spectrum disorder.

To date, information on associations between motor skills and executive functions (EF) in autistic children is limited. The purpose of this study was to compare motor skills and EF performance between autistic children and typically developing (TD) children and to examine the relationships between motor skills and EF in these two groups. Forty-eight autistic children and 48 TD children aged 6 to 12 years were recruited for this study. Motor skills were measured with the Bruininks-Oseretsky Test of Motor Proficiency-2 (BOT-2). EF was assessed with the Stroop Color and Word Test, the Wisconsin Card Sorting Task (WCST), and the Test of Attentional Performance: Go/No-go test. Independent sample t-tests were used to compare the BOT-2 scores and EF measures between autistic children and TD children. Pearson product-moment correlation and regressions were conducted to assess the relationships between the BOT-2 scores and the EF measures for each group. Results showed that autistic children scored significantly lower than TD children on all four BOT-2 composite scores and a total motor composite. Autistic children also demonstrated significantly lower levels of performance on all EF measures than TD children. Further, autistic children showed more significant associations between motor skills and EF than TD children, particularly pronounced in the domains of fine manual control and manual coordination to cognitive flexibility, as well as manual coordination and inhibitory control. Continued development of motor skills and EF in autistic children is important. The relationships between motor skills and EF were significant among autistic children, suggesting future research on promoting EF through motor skill interventions in autistic children is required.

Motor Adaptation Deficits in Children with Developmental Coordination Disorder and/or Reading Disorder.

Procedural learning has been mainly tested through motor sequence learning tasks in children with neurodevelopmental disorders, especially with isolated Developmental Coordination Disorder (DCD) and Reading Disorder (RD). Studies on motor adaptation are scarcer and more controversial. This study aimed to compare the performance of children with isolated and associated DCD and RD in a graphomotor adaptation task. In total, 23 children with RD, 16 children with DCD, 19 children with DCD-RD, and 21 typically developing (TD) children wrote trigrams both in the conventional (from left to right) and opposite (from right to left) writing directions. The results show that movement speed and accuracy were more impacted by the adaptation condition (opposite writing direction) in children with neurodevelopmental disorders than TD children. Our results also reveal that children with RD have less difficulty adapting their movement than children with DCD. Children with DCD-RD had the most difficulty, and analysis of their performance suggests a cumulative effect of the two neurodevelopmental disorders in motor adaptation.

Exploring an objective measure of overactivity in children with rare genetic syndromes

BackgroundOveractivity is prevalent in several rare genetic neurodevelopmental syndromes, including Smith-Magenis syndrome, Angelman syndrome, and tuberous sclerosis complex, although has been predominantly assessed using questionnaire techniques. Threats to the precision and validity of questionnaire data may undermine existing insights into this behaviour. Previous research indicates objective measures, namely actigraphy, can effectively differentiate non-overactive children from those with attention-deficit hyperactivity disorder. This study is the first to examine the sensitivity of actigraphy to overactivity across rare genetic syndromes associated with intellectual disability, through comparisons with typically-developing peers and questionnaire overactivity estimates.MethodsA secondary analysis of actigraphy data and overactivity estimates from The Activity Questionnaire (TAQ) was conducted for children aged 4-15 years with Smith-Magenis syndrome (N=20), Angelman syndrome (N=26), tuberous sclerosis complex (N=16), and typically-developing children (N=61). Actigraphy data were summarized using the M10 non-parametric circadian rhythm variable, and 24-hour activity profiles were modelled via functional linear modelling. Associations between actigraphy data and TAQ overactivity estimates were explored. Differences in actigraphy-defined activity were also examined between syndrome and typically-developing groups, and between children with high and low TAQ overactivity scores within syndromes.ResultsM10 and TAQ overactivity scores were strongly positively correlated for children with Angelman syndrome and Smith-Magenis syndrome. M10 did not substantially differ between the syndrome and typically-developing groups. Higher early morning activity and lower evening activity was observed across all syndrome groups relative to typically-developing peers. High and low TAQ group comparisons revealed syndrome-specific profiles of overactivity, persisting throughout the day in Angelman syndrome, occurring during the early morning and early afternoon in Smith-Magenis syndrome, and manifesting briefly in the evening in tuberous sclerosis complex.DiscussionThese findings provide some support for the sensitivity of actigraphy to overactivity in children with rare genetic syndromes, and offer syndrome-specific temporal descriptions of overactivity. The findings advance existing descriptions of overactivity, provided by questionnaire techniques, in children with rare genetic syndromes and have implications for the measurement of overactivity. Future studies should examine the impact of syndrome-related characteristics on actigraphy-defined activity and overactivity estimates from actigraphy and questionnaire techniques.

Spatial Accuracy and Variability in Dart Throwing in Children with Developmental Coordination Disorder and the Relationship with Ball Skill Items.

The present study aimed to examine precision and variability in dart throwing performance and the relationships between these outcomes and bouncing, throwing and catching tasks in children with and without DCD. Children between the ages of 8 and 10 years (n = 165) were classified according to results obtained on the Movement Assessment Battery for Children (MABC-2) and divided into three groups: 65 children with severe DCD (s-DCD), 45 with moderate DCD (m-DCD) and 55 typically developing children (TD). All children performed the dart throwing test and the ball skill items of the Performance and Fitness Test (PERF-FIT). The accuracy and variability of dart throwing tasks were significantly different between TD and s-DCD (p < 0.01), and also between m-DCD and s-DCD (p < 0.01). Participants with s-DCD were also found to perform significantly worse on all PERF-FIT ball skill items than m-DCD (p < 0.001), and m-DCD were significantly poorer than TD (p < 0.001). The dart score and coefficient of variation of the long-distance task appear to be significant predictors for the ball skills and explain between 24 to 29% of their variance. In conclusion, poor results in aiming tasks using darts in children with DCD corroborate with the explanation of deficits in predictive control since the tasks require ballistic movements.

Emotion dysregulation and depressive symptoms mediate the association between inhibitory control difficulties and aggressive behaviour in children with ADHD.

Impulsive aggressive behaviour, although not a core symptom, is often part of the clinical presentation of attention-deficit/hyperactivity disorder (ADHD). Recently, impulsive aggression has been attributed to emotion dysregulation, which is currently conceptualised as a transdiagnostic factor and seems to contribute to the co-occurrence of other problems in ADHD. Thus, this study investigated the presence of impulsive aggressive behaviour and explored whether emotion dysregulation mediates the relationship between inhibitory control difficulties and aggressive behaviour in children with ADHD. Because ADHD may act as a risk factor for the development of other conditions, such as internalising problems, we aimed to understand whether depressive symptoms contribute to this relationship. Seventy-two children were recruited from a hospital and the community, 38 of whom had ADHD and 34 were typically developing (TD). Parents completed the Child Behaviour Checklist, the Behaviour Rating Inventory of Executive Function, and the Emotion Regulation Checklist. Simple mediation and serial mediation models were performed to test our hypotheses. Aggressive behaviour was significantly higher in ADHD children compared to TD children. Emotion dysregulation fully mediated the relationship between inhibitory control difficulties and aggressive behaviour in ADHD children. Adding depressive symptoms to the model increased the explained variance in aggressive behaviour. The main result of our study supports the role of emotion dysregulation and depressive symptoms in mediating the relationship between inhibitory control difficulties and impulsive aggressive behaviour in children with ADHD. This highlights that aggressive behaviour is, in part, a result of the inability of the child to appropriately regulate their emotions. Future interventions may be tailored to improve emotion regulation skills to address aggressive behaviour.

[Analysis of language and influencing factors of children with speech disorder in Beijing].

Objective: To investigate the features and influencing factors of language in children with various types of speech disorders. Methods: A case-control study was carried out, 262 children with speech disorder had been diagnosed at the language-speech clinic of the Center of Children's Healthcare, Children's Hospital, Capital Institute of Pediatrics from January 2021 to November 2023, the children with speech sound disorder as the speech sound disorder group, the children with developmental stuttering as the stuttering group. There were 100 typically-developed children who underwent physical checkups at the Center of Healthcare during the same period as the healthy group. All children experienced a standardized evaluation of language with diagnostic receptive and expressive assessment of mandarin-comprehensive(DREAM-C) and questionnaire, One-way ANOVA and LSD test were conducted to compare the differences in overall language, receptive language, expressive language, semantics, and syntax scores among 3 groups of children. According to the results of DREAM-C, the children with speech disorder were divided into language normal group and language delay group. Chi-square test and multivariate Logistic regression were implemented to analyze the association between the linguistic development of children with speech disorder and potential influential factors. Results: There were 145 children in the speech sound disorder group, including 110 males and 35 females respectively, with an age of (5.9±1.0) years; 117 children in the stuttering group, including 91 males and 26 females, with an age of (5.8±1.0) years; 100 children in the healthy group, including 75 males and 25 females, with an age of (5.7±1.2) years. The variations in overall language, expressive language, and syntax scores among 3 groups of children were statistically significant (92±18 vs.96±11 vs. 98±11, 81±18 vs. 84±14 vs. 88±13, 87±16 vs. 89±11 vs. 91±10, F=5.46, 4.69, 3.68, all P<0.05). Pairwise comparison revealed that the speech sound disorder group had lower scores in overall language, expressive language, and syntactic compared to the healthy group, and the differences were statistically significant (all P<0.01) and the overall language score was lower than that of children with stuttering (P<0.05). In terms of overall language and expressive language, there was a statistically significant difference in the incidence of language delay among the three groups of children (15.9% (23/145) vs. 20.5% (24/117) vs. 7.0% (7/100), 46.2% (67/145) vs. 39.3% (46/117) vs. 26.0% (26/100); χ2=7.93, 10.28; both P<0.05). In terms of overall language, the stuttering group took up the highest proportion. In terms of expressive language, the speech sound disorder group accounted for the highest amount. The incidence of language delay in children with speech disorder was 44.3% (116/262). Non-parent-child reading, daily screen time ≥1 hour and screen exposure before 1.5 years of age are risk factors for the development of language in children with speech disorder (OR=1.87, 2.18, 2.01; 95%CI 1.07-3.27, 1.23-3.86, 1.17-3.45; all P<0.01). Negative family history are protective factors for the progress of language ability (OR=0.37, 95%CI 0.17-0.81, P<0.05). Conclusions: Children with speech disorder tend to have easy access to language delay, especially in expressive language and syntax. The occurrence of language delay in children with speech disorder is tightly connected with factors such as the family medical history, parent-child reading, screen time, etc. Attention should be paid to the development of language in children who suffer from speech disorder.

Associations Between Joint Attention, Supported Joint Engagement and Language in TD Children and Children with ASD: Potential Sources of Individual and Group Differences in Language Outcomes

ABSTRACT Joint Attention (JA) and Supported Joint Engagement (Supported JE) have each been reported to predict later language development in typically developing (TD) children and children with Autism Spectrum Disorder (ASD). In this longitudinal study including 33 TD children (20 months at V1) and 30 children with ASD (33 months at V1), the contributions of JA and Supported JE to later language, assessed via standardized tests and spontaneous speech, were directly compared. Frequency and durations of JA and Supported JE episodes were coded from 30-minute interactions with caregivers; subsequent language skills were assessed two years later. JA duration in the ASD group significantly predicted later standardized and spontaneous language, most strongly in the low-verbal ASD subgroup. Supported JE measures did not positively predict later language in either group. These findings suggest that JA played a larger role with children with ASD with low-verbal abilities, but not with children with ASD with high-verbal abilities nor with the TD children. The current study adds to existing literature by providing further support for studying children with ASD as two subgroups based on their verbal abilities (high vs low), as well as directly comparing the effects of JA and Supported JE on later language development in such groups. Implications for further research are discussed.

How do Children with Intellectual Disabilities Empathize in Comparison to Typically Developing Children?

Two studies were conducted to better understand how children with intellectual disabilities (ID) empathize with the feelings of others during social interactions. The first study tested hypotheses of developmental delay or difference regarding empathy in 79 children with ID by comparing them with typically developing (TD) children, matched for developmental age or chronological age. The second study examined specific aspects of empathy in 23 children with Down syndrome (DS), compared with 23 nonspecific ID children, matched for developmental age, and TD children, matched for developmental age or chronological age. An empathy task was administered to the children while their parents completed the French versions of the Empathy Questionnaire and the Griffith Empathy Measure. The first study showed that ID children showed delayed empathy development but were perceived by their parents as deficient in cognitive empathy. The second study showed that DS children were perceived as being more attentive to the feelings of others than TD children and non-specific ID children, matched for developmental age, and as having affective empathy that was similar to that of TD children matched for chronological age. These studies have drawn attention to delays or differences in different dimensions of empathy in children with ID and DS, which need to be taken into account in interventions.

Age-related differences in auditory spatial processing revealed by acoustic change complex.

The auditory spatial processing abilities mature throughout childhood and degenerate in older adults. This study aimed to compare the differences in onset cortical auditory evoked potentials (CAEPs) and location-evoked acoustic change complex (ACC) responses among children, adults, and the elderly and to investigate the impact of aging and development on ACC responses. One hundred and seventeen people were recruited in the study, including 57 typically-developed children, 30 adults, and 30 elderlies. The onset-CAEP evoked by white noise and ACC by sequential changes in azimuths were recorded. Latencies and amplitudes as a function of azimuths were analyzed using the analysis of variance, Pearson correlation analysis, and multiple linear regression model. The ACC N1'-P2' amplitudes and latencies in adults, P1'-N1' amplitudes in children, and N1' amplitudes and latencies in the elderly were correlated with angles of shifts. The N1'-P2' and P2' amplitudes decreased in the elderly compared to adults. In Children, the ACC P1'-N1' responses gradually differentiated into the P1'-N1'-P2' complex. Multiple regression analysis showed that N1'-P2' amplitudes (R2 = 0.33) and P2' latencies (R2 = 0.18) were the two most variable predictors in adults, while in the elderly, N1' latencies (R2 = 0.26) explained most variances. Although the amplitudes of onset-CAEP differed at some angles, it could not predict angle changes as effectively as ACC responses. The location-evoked ACC responses varied among children, adults, and the elderly. The N1'-P2' amplitudes and P2' latencies in adults and N1' latencies in the elderly explained most variances of changes in spatial position. The differentiation of the N1' waveform was observed in children. Further research should be conducted across all age groups, along with behavioral assessments, to confirm the relationship between aging and immaturity in objective ACC responses and poorer subjective spatial performance. ACCs evoked by location changes were assessed in adults, children, and the elderly to explore the impact of aging and development on these differences.

Histological analysis of the medial gastrocnemius muscle in young healthy children.

Introduction: Histological data on muscle fiber size and proportion in (very) young typically developing (TD) children is not well documented and data on capillarization and satellite cell content are also lacking. Aims: This study investigated the microscopic properties of the medial gastrocnemius muscle in growing TD children, grouped according to age and gender to provide normal reference values in healthy children. Methods: Microbiopsies of the medial gastrocnemius (MG) muscle were collected in 46 TD boys and girls aged 2-10years subdivided into 4 age groups (2-4, 4-6, 6-8 and 8-10years). Sections were immunostained to assess fiber type cross-sectional area (fCSA) and proportion, the number of satellite cells (SC), capillary to fiber ratio (C/F), capillary density for type I and II fiber (CFD), capillary domain, capillary-to-fiber perimeter exchange index (CFPE) and heterogeneity index. fCSA was normalized to fibula length2 and the coefficient of variation (CV) was calculated to reflect fCSA intrasubject variability. Results: Absolute fCSA of all fibers increased with age (r = 0.72, p < 0.001) but more in boys (+112%, p < 0.05) than in girls (+48%, p > 0.05) Normalized fCSA, CV and fiber proportion did not differ between age groups and gender. C/F was strongly correlated with age in boys (r = 0.83, p < 0.001), and to a lesser extent in girls (r = 0.37, p = 0.115), while other capillary parameters as well as the number of SC remained stable with increasing age in boys and girls. Discussion: This study provides reference values of histological measures in MG according to age in normally growing boys and girls. These data may be used as a reference to determine disease impact and efficacy of therapeutic approach on the muscle.

Impaired cortical tracking of speech in children with developmental language disorder.

In developmental language disorder (DLD), learning to comprehend and express oneself with spoken language is impaired, but the reason for this remains unknown. Using millisecond scale magnetoencephalography (MEG) recordings combined with machine learning models, we investigated whether the possible neural basis of this disruption lies in poor cortical tracking of speech. The stimuli were common spoken words (e.g., 'dog', 'car', 'hammer') and sounds with corresponding meanings (e.g., dog bark, car engine, hammering). In both children with DLD (10 boys and 7 girls) and typically developing (TD) control children (14 boys and 3 girls), aged 10-15 years, the cortical activation to spoken words was best modeled as time-locked to the unfolding speech input at ∼100 ms latency between sound and cortical activation. Amplitude envelope (amplitude changes) and spectrogram (detailed time-varying spectral content) of the spoken words, but not other sounds, were very successfully decoded based on time-locked brain responses in bilateral temporal areas; based on the cortical responses, the models could tell at ∼75-85% accuracy, which of two sounds had been presented to the participant. However, the cortical representation of the amplitude envelope information was poorer in children with DLD compared to TD children at longer latencies (at ∼200-300 ms lag). We interpret this effect as reflecting poorer retention of acoustic-phonetic information in short-term memory. This impaired tracking could potentially affect the processing and learning of words as well as continuous speech. The present results offer an explanation for the problems in language comprehension and acquisition in DLD.Significance statement The neural basis of impaired speech processing in developmental language disorder (DLD) was probed with magnetoencephalography (MEG), natural spoken words and sounds, and state-of-the-art machine learning models. Cortical tracking of speech was normal at initial stages, but impaired at syllable-level latency, reflecting problems in maintaining cortical memory representations of the incoming speech across the word. This offers an explanation for the problems in DLD in identifying words and learning new ones.

Exact and approximate calculation and uncertain decision-making in children and adults: Evidence from fuzzy trace theory

The present study aimed to explore the role of exact and approximate calculation in predicting uncertain decision-making in children and emerging adults and the influence of intelligence on their uncertain decision-making was simultaneously considered. In the first study, forty emerging adults and fifty-four typically developing (TD) children completed the uncertain decision-making task—Iowa Gambling Task (IGT), exact calculation task, and approximate calculation task. In the second study, we further included data from forty-six intellectually gifted children with the same age as the TD children to investigate the relationship between calculation and uncertain decision-making performance. The results showed that emerging adults' and intellectually gifted children's IGT performance was superior to TD children. Exact and approximate calculation played different roles in predicting IGT performance in emerging adults and TD children: after controlling their intelligence scores, TD children's exact calculation negatively predicted their uncertain decision-making, whereas emerging adults' approximate calculation positively predicted their uncertain decision-making. Furthermore, intellectually gifted children's approximate calculation was positively associated with their uncertain decision-making, which is similar to emerging adults. This study verified and expanded fuzzy trace theory, and it shed light on developing and improving approximate calculation ability, which is beneficial to the increased ability of uncertain decision-making.